The present invention relates to apparatus for leading the tail of a web of paper. More particularly, the invention relates to apparatus for guiding the tail of the web of paper before the widening of said web in connection with different parts of a paper machine, such as the calender, size press, dewatering press, smoothing press or other similar parts.
The DURAND.TM. tail carrier system of the prior art comprises a belt carrier and an incorporated suction box producing a suction effect by means of which the tail is adhered to the transfer belt. A disadvantage of this known apparatus is the fact that the transfer belts require their own reversing rollers and driving systems, and the placing of these into already cramped spaces causes problems. In addition, these apparatuses consume relatively much suction air and energy due to the suction boxes.
The operation of the AIRLIFT.TM. carrier system of the prior art is based on the Coanda effect. This apparatus comprises a nozzle orifice and a carrier surface connected thereto, along which air is blown at a relatively high speed. This creates an air cushion of reduced pressure, having a previously known carrying effect. A disadvantage of this apparatus is that it consumes much blowing air and thereby much energy. In addition, a disadvantage may be considered the fact that the blowing air tends to get packed into the nips through which the tail of the web is carried. This results in difficulties in getting the tail of the web to pass the nip. The packed air is guided aside and light paper is carried by the air current.